Adsorbent media with Li exchanged zeolite
An adsorbent media composition has a finished media lithium-exchanged zeolite X (LiX) with a finished Li content in a range from 96% to 83%, based on the total cation equivalents in the LiX. The adsorbent media composition is obtained from a slurry comprising water, a LiX precursor having a pre-media production Li content that is greater than the finished media LiX Li content, and another media component material, such as fibers. The water used to produced the media has a specific conductance in a range from 2.2 μSiemens/cm to 150 μSiemens/cm. The finished media LiX has a monovalent cation (Na, K, Rb, Cs and combinations thereof) in a range from 0.05% to 3%, based on the total equivalents of exchangeable cations in the finished media LiX.
1. An adsorbent media composition comprising: a first media component material selected from the group consisting of polymeric fibers, inorganic fibers, natural fibers, carbon fibers and mixtures thereof; a second media component material having at least 30 weight percent of an adsorbent composition comprising a finished media lithium-exchanged zeolite X (LiX), the finished media LiX having a finished Li content, wherein the finished media LiX is derived from a LiX precursor having a pre-media production Li content; wherein (a) the finished media LiX Li content is reduced relative to the LiX precursor Li content, (b) the finished media LiX Li content is in a range from 96% to 83%, based on the total cation equivalents in the LiX, and (c) the adsorbent media composition is obtained from a slurry mixture comprising water, the pre-media production LiX and the first media component material, wherein (i) the water has a specific conductance in a range from 2.2 .mu.Siemens/cm to 150 .mu.Siemens/cm; (ii) the finished media LiX has a monovalent cation content in a range from 0.05% to 3%, based on the total equivalents of exchangeable cations in the finished media LiX, wherein the monovalent cation is selected from the group consisting of Na, K, Rb, Cs, and combinations thereof; and (iii) the finished media LiX has a divalent cation content in a range from 0.05% to 15%, based on the total cation equivalents in the finished media LiX, wherein the divalent cation is selected from the group consisting of Ca, Mg, Sr, Ba, and combinations thereof.
2. The media of claim 1 , wherein the water used to make the slurry mixture has concentrations of monovalent cations and divalent cations, respectively, wherein the total moles of monovalent cations in the water are less than or equal to 3% of the total lithium equivalents in the original zeolite and the total moles of divalent cations in the water are less than or equal to 15% of the total lithium equivalents in the zeolite, so that the finished media LiX has a monovalent cation content in the range from 0.05% to 3%, based on the total percent of exchangeable cations in the finished media LiX.
3. The media of claim 1 , wherein the zeolite X has a Si/Al ratio from 1.0 to 1.5.
4. The media of claim 1 ,comprising at least 60 weight-percent of adsorbent.
5. The media of claim 1 , having a substantially uniform thickness of 0.10 mm to 1.00 mm.
6. The media of claim 1 , wherein the polymeric fiber is a para-aramid.
7. The media of claim 1 , wherein the slurry mixture further comprises organic latex and inorganic oxide binders.
8. A method for separating a gas mixture having at least a first gas component and a second gas component, the method comprising: introducing the gas mixture into an adsorption zone having at least the adsorbent media composition of claim 1 , 2 , 3 , 4 , 5 , 6 , or 7 , and recovering a gas product stream enriched in the at least first gas component, which is less preferentially adsorbed by the finished media LiX relative to the at least second gas component.
9. The method of claim 8 , wherein the gas mixture is air and the at least first gas component is oxygen and the at least second gas component is nitrogen.